Flotation recovery of minerals



Patented Sept. 15, 1931 UNITED STATES PATENT OFFICE LUDWIG J. CHRISTMANN, OF JERSEY CITY, AND STUART A. FALCONER, F ELIZABETH, NEW JERSEY, ASSIGNORS TO AMERICAN CYANAMID COMPANY, OF NEW YORK, N. Y.,

A CORPORATION OF MAINE FLOTATION RECOVERY OF MINERALS 1T0 Drawln g.

The object of this invention is the successful separation of oxide minerals from ores containing the same. Many reagents are known which are promotors for sulfide ores but not all sulfide reagents are effective in the flotation of so-called oxidized minerals. On

' the other hand, reagents for oxidized minerals will in general assist in the flotation of sulfides.

By an oxidized mineral we mean a heavy metal such as lead, zinc, copper, etc., in combination with elements or groups of elements other than sulfur.

We have discovered that the alkaline metal salts of hydroaromatic xanthates, for example, potassium cyclohexyl xanthate, potassium methyl cyclohexyl xanthate, are efi'ective reagents in the flotation of oxide ores. We prefer to use these reagents in combination go with other reagents. These other reagents may be varied considerably, but a hydroaromatic xanthate is always essential in the practice of our invention.

The structural formula for this type of re- ?.5 agent is:

where Me is a metal of the alkaline type, such as sodium, potassium, ammonium, calcium, etc. R is analkyl group, such as methyl, ethyl, etc., or an aryl group, such as phenyl, naphthyl, etc., or hydrogen. R may be placed in the ortho, meta or para positions.

We have prepared cyclohexyl xanthate by the following method:

50 g. of cyclohexylanol (hexalin) and 15 g. of potassium hydroxide were heated under reflux until the KOH was in solution. The solution was stirred, cooled and 200 cc. of ethyl ether added. The mixture was placed in an ice bath and 15 cc. of carbon bisulfide in 100 cc. of ether wereslowly added. The precipitate of potassium cyclohexyl xanthate was filtered, washed with ether, and allowed to air-dry. To purify the above it was dissolved in acetone, the undissolved portion,

Application filed January 9, 1930. Serial No; 419,733.

filtered oil, and the filtrate diluted with benzol and the precipitate thrown down was a cream colored product of high purity.

The potassium o. methylcyclohexyl xanthate was prepared in an analogous manner.

The following examples are illustrative of the practice of our invention on the oxidized lead ore of the North Lily Mine of the International smelting Company.

1200 g. of ore, 1200 cc. of water and 5.0 lbs. of crude monoammonium phosphate per ton of ore were ground in a laboratory rod mill for 12 minutes. minus 200. The rod mill charge was transferred to a laboratory mineral separation subareation machine and diluted to 22% solids. The reagents were added to the machine and a mineralized froth collected for 20 minutes.

Reagents in pounds per ton to mill Ammo. phos. (crude mono-am- Under the same conditions a run made with potassium o. methylcyclohexyl xanthate showed:

Reagents in pounds per ton to mill Ammo. phos. (crude mono-ammonium phosphate) 5.0 5.0

To flotation machine Ammonium n. dibutyl dithiophosphate 1.25 1.25 Potassium o. methylcyclohexyl xanthate 4.0 Percent lead in heads 26.6 26.3 Percent lead in concentrates 38.2 47.45 Percent lead in tails 19.59 5.38 Percent lead in recovered 54.5 89.8

The mesh of the feed is 60% vary the In the practice of our invention we may details considerably from the illustrations given above. We may use other rea ents besides the ammonium n. dibutyl dithiopho'sphate and the crude monoammonium phosphate. 1 For example, we may use other xanthates infplace of dibutyl dithiophosphate orv other dithiophosphates. The essential feature of our invention is the use of a hydroaromatic xanthate of which potassium cyclohexyl xanthate and potassium o.

methylcyclohexyl xanthates are. types. Other homologues of 7 may be used. Y We consider that this type of h droaromatic xanthatev nucleus is responsible for the increased activity of these xanthates over the ordinary xanthates of the aliphatic series which are now in use.

What we claim is:

1. A method of recovering minerals from ores-which comprises subjecting an oxidized ore to a froth flotation operation in thepresence of a salt of a cyclohexyl xanthate as a promotor.

2. A method of recovering minerals from I ores which comprises subjecting an oxidized cyclohexyl xanthate' ence of a salt of a cyclohexyl xanthate as a promotor in conjunction with another pro motor, and a conditioner.

In testimony whereof, we have hereunto subscribed our names this 2nd day of January,1930. I Q I I LUDWIG J. CHRISTMANN.

S. A. FALCONER.

ore to a froth flotation operation in the pres-- ence of a salt of a substituted xanthate as a promotor.

3.. A method of recovering minerals from ores which comprises subjecting an oxidized ore to a froth flotation operation in the presence of potassium methyl cyclohexyl xanthate asa promotor. I v

4. A method of recovering minerals from ores which comprises subjecting an oxidized ore to a froth flotation operation in the presence of a Promoter having the following structural formula:

ores which comprises subjecting 'an oxidized ore to a froth flotationoperation in the presence of asalt of a cyclohexyl xanthate as a promotor in conjunction with a dithiophosphate. I

I 7. A method of recovering minerals from ores which comprises subjecting an oxidized ore to, a froth flotation operation in the pres- 

